436
STEPHENSON’S PATENT
middle of the cross head, and are held upon the end of the connecting rod, T, by
the iron strap, X, fitted between the flanches of the brasses and fixed to the connecting
rod by the key and gib Y, so as to hold them firmly and steadily together. The
key Z is put through the connecting rod and strap close to the inner brass U; the
holes in the strap being made larger than the key at the outer end, so that the key
bears against the brass U, and forces it against the brass on the cross head. The
connecting rod moves upon the cross head, and the friction causes the brasses
to wear, so that they require tightening up occasionally by driving in the key
Z farther, and bringing them nearer together; a little space is left between the
brasses to allow for this. Small screws are inserted opposite to each of the keys,
and are screwed against them when they are driven into their places to prevent
their jolting loose.
The construction of the other end of the connecting rod is shewn on the same
scale in figs. 20 and 21, which are a plan and a longitudinal section of it.
Fig. 20.
Fig. 21.
A is the end of the connecting rod, which is enlarged at B B to five inches and
three quarters wide, and cut out to an octagonal shape at the end, fitting the brass bear
ing C. The other brass, D, is similar to it, and they are both three inches wide, with